Friss transfer formula is given by _____

• A. (P_r = P_t G_r G_t ( frac{ }{4 R})^2 )
• B. (P_r = P_t G_r G_t ( frac{ }{4 R}) )
• C. (P_r = frac{P_t G_r G_t}{ frac{ }{4 R}} )
• D. (P_r = P_t G_r G_t ( frac{ }{4 R^2}) )